A location-based service (LBS) refers to a service that provides location-dependent information such as road guide, surrounding facility information inquiry, traffic information, location search, or the like based on the location of a portable user terminal 100. For the purpose of providing the location-based service in the portable user terminal 100, it is necessary to grasp the location of the portable user terminal 100. For example, the technology for grasping the location of the portable user terminal 100 by using signals received from GPS satellites is widely used.
In addition, it is possible to estimate/measure the location of the portable user terminal 100 by using a wireless network. For example, a fingerprinting-based positioning scheme using the signal strength measured at a plurality of predefined reference locations may be used. In this case, the strength value/pattern of a wireless signal collected at each location may be referred to as a wireless local area network (WLAN) fingerprint at the corresponding location, and the database of fingerprints with each of which a reference location is tagged may be referred to as a radio map.